As you are considering what equipment to buy for next year’s hay making season or are you just looking at your hay test results and wondering why ash content is reported. A recent article by Rebecca Kern-Lunbery (Ward Laboratories) in Progressive Forage showed that many producers bale more soil than they want to. The following is an excerpt of this article:
Make sure your forage samples don’t contain too much ash based on your hay quality report (which can mean soil contamination). Ash is the total mineral content of a feed and has two sources. Endogenous ash is from the plant and is bioavailable, providing micronutrients to the animal. Exogenous ash is from soil contamination of the feed. Most forages range between 8%-10% ash with 4%-6% representing the endogenous portion. Extremely soil-contaminated forages could contain as much as 25% ash. So, almost one-quarter of the dry matter in that forage is just dirt. A good goal is to make and feed hay with less than 15% ash.
So what causes soil contamination of harvested forages? One common reason that soil can end up in our stored forages is dry conditions. When field conditions are dryer, it is easier for the rake to pull up soil particles and incorporate them into the bale. And there have been many months with dry conditions in recent years. What can we do to prevent soil contamination of our stored forages? Here are four tips to prevent contaminating stored forages with soil:
- Cut forages 3-4 inches off the ground. This can help optimize forage quality by not incorporating the most fibrous portion of the plant. More importantly, this practice will leave more ground cover and give some protection from soil erosion. It will also allow the forage to regrow faster.
- Rake as little as possible. I have known some producers who live in climates where humidity is an issue, and they rake the windrows to turn them to ensure the hay is completely dry. Avoid this practice unless it is absolutely necessary.
- Pay attention and adjust your equipment. Prior to cutting or baling, ensure your equipment is properly adjusted to prevent unnecessary disturbance of the ground. Also, if you are seeing a trail of dust, stop and adjust things to reduce the amount of soil being incorporated into the bale.
- Graze. Forgoing the harvesting process will ensure animals have the ability to choose the forage they consume and eliminate the possibility of consuming a lot of dirt.
You might ask “What’s the harm in my cattle eating a little dirt?” A little dirt is ok, but if there is much dirt it can affect animal health. The problem with soil-contaminated feeds is that the soil could cause compaction within the omasum, abomasum or beginning of the small intestine. An impaction would not allow other digesta to pass through. An impaction could cause cattle to go off feed, if it is serious enough. The more likely issue would be a decrease in performance due to the dry matter intake (DMI) the ash is taking up. Because cattle typically consume 2% of their bodyweight in dry matter, consumption of soil-contaminated feed can result in a considerable amount of the feed having no nutritional value, thereby resulting in decreased performance for the animal.
In addition to the risk of impaction, soil contamination can also affect mineral nutrition. Iron from the soil can interfere with copper absorption at 250 parts per million. Also, the bioavailability of minerals from the soil is low. So if you are feeding a forage high in ash, mix it with feeds that have a low ash content to minimize impaction risk and performance losses. Furthermore, if high iron levels are present, increased copper supplementation might be necessary.
In conclusion, ash is an often-overlooked parameter on forage reports. At high levels, it can indicate a soil contamination issue. Soil in forages can reduce forage quality and have a negative impact on livestock health. Monitoring ash levels in forages can be important in identifying areas for forage production improvement as well as ensuring forages are managed and fed out to ensure top-tier nutrition and health for our livestock. To read Rebecca’s full article go to the Progressive Forage website. The direct link is https://www.agproud.com/topics/102-progressive-forage
PHOTO: Man at work on the tractor with hay baler. (Adobe Stock │ #267996708 – Mirko)
